1. Field of the Invention
The present invention relates to a light source apparatus and an optical scanner including the light source apparatus.
2. Description of the Related Art
When a light source apparatus, which includes a semiconductor laser, a coupling lens, and a cylindrical lens, is assembled, it is necessary that the optical axes of the coupling lens and the cylindrical lens should be coincident with the optical axis of the semiconductor laser.
As shown in FIGS. 7A and 7B, a conventional light source apparatus 200 includes a semiconductor laser 210, a coupling lens 220, and a cylindrical lens 230. The light source apparatus 200 is assembled by fixing these respective parts to a base 250. In particular, the coupling lens 220 is fixed by the adhesion at a predetermined position in a barrel 225. Subsequently, the barrel 225 including the fixed coupling lens 220 fixed thereto and the cylindrical lens 230 are fixed to the base 250 by means of a method such as the adhesion or the like. The semiconductor laser 210 is fixed to a circular opening 262 of a holder 260 by means of, for example, the press-in or forcible insertion, and then the holder 260 is adhered to the base 250. Accordingly, the light source apparatus 200 is assembled. In this procedure, the high accuracy is required especially for the positional adjustment and the fixation of the coupling lens 220 and the semiconductor laser 210. Any deviation of the optical axis of the semiconductor laser 210 or the coupling lens 220 immediately affects the light condensing accuracy (light collecting accuracy, or light converging accuracy) of the light source apparatus.
Japanese Patent Application Laid-open No. 2001-311892 also discloses a similar light source apparatus, wherein a coupling lens is fixed to a first holding member (LD base), a cylindrical lens is fixed to a second holding member (holder), and the first holding member and the second holding member are fixed.
However, in the case of the conventional light source apparatus, a plurality of holding members are provided between the coupling lens and the cylindrical lens. Therefore, a problem arises such that the error is increased, and any desired light condensing accuracy is not obtained with the laser beam emitted from the light source.